DOCSLIB.ORG

Isolation of Genomic Dna from Five Species of Euphorbiaceae Without Liquid Nitrogen

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Isolation of Genomic Dna from Five Species of Euphorbiaceae Without Liquid Nitrogen ISOLATION OF GENOMIC DNA FROM FIVE SPECIES OF EUPHORBIACEAE WITHOUT LIQUID NITROGEN D. DHAKSHANAMOORTHY1,2,*, R. SELVARAJ2, A. CHIDAMBARAM2 The isolation of intact, high-molecular mass genomic DNA is essential for many molecular biology applications including PCR, endonuclease digestion, southern blot analysis, and genomic library construction. Many protocols are available for the extraction of genomic DNA from plant tissue, and all the protocols have used expensive and hazardous chemical-liquid nitrogen for grinding plant material or DNA isolation kits for extraction. In the present study a modified CTAB (Cetyl trimethyl ammonium bromide) method has been used for isolation of genomic DNA from the leaves of five species of Euphorbiaceae viz., Ricinus communis, Excoecaria robusta, Hevea brasiliensis, Jatropha multifida and Jatropha curcas. Key step in the modified CTAB method is the use of alcohol for submerging leaf tissue instead of grinding it in liquid nitrogen. The protocol described (alcohol fixation) has yielded genomic DNA with excellent quality, which is comparable to those results of liquid nitrogen ground leaves. The genomic DNA isolated has an excellent absorbance (A260/A280) ratio observed between 1.80 and 2.00, indicating good genomic DNA without contaminants, highly suitable for PCR amplification. Key words: CTAB; Euphorbiaceae; Genomic DNA; Latex-yielding plants; Without liquid nitrogen. INTRODUCTION DNA marker technology has been rapidly developing and many techniques that seemed unfeasible before are now routinely used. With the development of various molecular markers based on PCR technique such as RAPD, SSR, ISSR, STR, AFLP, and RFLP, molecular biology has greatly enhanced the speed and efficiency in crop improvement and breeding programmes, rDNA technology and construction of genomic DNA library. In general, it is difficult to extract and purify high-quality DNA from latex-yielding plants because of the presence of large quantities of secondary metabolites, polysaccharides, and proteins such as tannins, 1 Department of Plant Biology and Biotechnology, Periyar Govt. Arts College, Cuddalore, Tamilnadu, India. * Corresponding author: Dr.D. Dhakshanamoorthy, Department of Plant Biology and Biotechnology, Periyar Govt. Arts College, Cuddalore, Tamilnadu, India. Mobile: 099656 25438, E-mail: [email protected]. 2 Division of Biotechnology and Molecular Biology, Department of Botany, Annamalai University, Annamalainagar-608 002, Tamilnadu, India. ROM. J. BIOL. – PLANT BIOL., VOLUME 58, No. 1, P. 3–8, BUCHAREST, 2013 4 D. Dhakshanamoorthy, R. Selvaraj, A. Chidambaram 2 alkaloids and polyphenols. These compounds interfere by precipitating along with the DNA, thus degrading its quality and reducing the yield. Most extraction methods use expensive and hazardous chemicals for grinding plant tissue in liquid nitrogen to break down the cell wall of plants (Sharma et al. 2003) or freeze-drying (Michiels et al. 2003). Procurement and storage of liquid nitrogen may be difficult and expensive for many laboratories and transportation and handling of the same is also cumbersome. A good extraction procedure is considered to be one which results in DNA of reasonable purity without using the harmful chemical- liquid nitrogen. Thus, a method not requiring use of liquid nitrogen would be helpful to the researchers in remote areas. We have described here, an efficient protocol for isolating high-molecular PCR amplifiable DNA from leaves of five species of Euphorbiaceae viz., Ricinus communis, Excoecaria robusta, Hevea brasiliensis, Jatropha multifida and Jatropha curcas. MATERIALS AND METHODS The samples of young and tender leaves of five species of Euphorbiaceae viz., R. communis, E. robusta, H. brasiliensis, J. multifida and J. curcas were collected from the Botanical gardens of Tamilnadu Agricultural University (TNAU), Coimbatore, Tamilnadu. After washing the plant tissue with sterile water and subsequently with 70 per cent alcohol, 100mg of fresh leaf tissue of above species was taken and then it was chopped into fine pieces and subjected to genomic DNA isolation. Simultaneously leaves of same species were dried in an electric oven at 60° C for 24 hrs and 100mg of dry leaves were processed for extraction of genomic DNA. Genomic DNA was extracted from both fresh and dry leaves by adopting the CTAB method outlined by Doyle and Doyle (1990) without using liquid nitrogen. About 100mg of leaf tissue was submerged in absolute alcohol for an hour instead of grinding it in liquid nitrogen and put in a 2ml edppendorf tube. To grind the sample 1.5ml of CTAB extraction buffer (2% CTAB, 100mM Tris-HCl, 1.4M NaCl, 20mM EDTA di-sodium salt, 0.2M Mercaptoethanol 2% PVP pH 8.0) was added and incubated at 65° C for 60 min. Simultaneously liquid nitrogen ground leaves (fresh and dry) were also processed with CTAB buffer for comparison. The above mixtures were added with equal volume of chloroform: isoamylalcohol (24:1) and centrifuged at 5000rpm for 20min. After adding equal volume of cold isopropanol, the supernatant was stored at -20° C for an hour. Thereafter, the mixture was centrifuged at 3000rpm for 10min. The pellet was collected and treated with RNase (10mg/ml) for 30min. at 37° C. After an incubation period, 3M sodium acetate and absolute cold ethanol were added to the mixture and it was again incubated at –20° C for an hour and centrifuged at 3000rpm for 10min. After extracting the pellet with 70% ethanol twice it was air-dried and dissolved in 100µl of Milli Q water. The genomic DNA 3 DNA isolation without liquid nitrogen 5 isolated was quantified spectrometrically by measuring absorbance at 260nm and DNA was diluted to make a working solution for trial run of RAPD-PCR in thermal cycler. RESULTS AND DISCUSSION Genomic DNA isolated from fresh and dry leaves of five species of Euphorbiaceae using CTAB method with/without using liquid nitrogen are shown in Table 1. Genomic DNA yield from alcohol fixed fresh leaves ranged from 263 to 336 µg per gram fresh weight with A260/A280 absorbance ratio between 1.80 and 2.00, indicating good genomic DNA free from polysaccharides, protein and secondary metabolites such as tannins, alkaloids, and polyphenols, whereas DNA isolated from dry leaves of alcohol fixed samples ranged from 187 to 256 µg per gram dry weight but A260/A280 absorbance ratio was below 1.80, which ranged from 1.55 to 1.62, indicating high level of contamination with proteins, polysaccharides and polyphenols. Table 1 Quality and quantity of genomic DNA isolated from fresh and dry leaves of Ricinus communis, Excoecaria robusta, Hevea brasiliensis, Jatropha multifida and Jatropha curcas using a modified CTAB method (without/with liquid nitrogen) Without liquid nitrogen With liquid nitrogen (alcohol fixed leaves) Fresh Dry Fresh Dry Species leaves leaves leaves leaves DNA DNA DNA DNA yield A260/A280 yield A260/A280 yield A260/A280 yield A260/A280 (µg/g) (µg/g) (µg/g) (µg/g) Ricinus 286±15.00ab 1.90±0.10a 187±17.00a 1.58±0.04ab 290±10.00b 1.88±0.03ab 126±11.00a 1.62±0.10a communis Excoecaria 286±25.00ab 1.87±0.10a 200±19.00a 1.55±0.05a 233±15.30a 1.88±0.04ab 196±15.00b 1.66±0.08a robusta Hevea 263±17.00a 1.87±0.05a 200±10.00a 1.62±0.05ab 233±20.00a 1.83±0.02a 193±17.00b 1.63±0.10a brasiliensis Jatropha 336±15.27c 1.93±0.08a 253±24.00a 1.56±0.01a 296±15.00b 1.93±0.06a 240±21.00b 1.60±0.01a multifida Jatropha 320±20.00bc 1.91±0.07a 256±20.81a 1.60±0.04ab 283±20.81b 1.88±0.04ab 203±20.00b 1.64±0.02a curcas ± = Standard Deviation (SD). Values followed by different letters (abc) are significantly different at α = 0.05% level according to Duncan’s Multiple Range Test (DMRT) (n = 3 for all five species). These compounds interfere by precipitating along with the DNA, thus degrading its quality and reducing the yield. In the present study, the purity of DNA isolated from alcohol fixed / liquid nitrogen ground dry leaves was however 6 D. Dhakshanamoorthy, R. Selvaraj, A. Chidambaram 4 questionable because of the presence of a high level of brown-coloured compounds which released upon cell lysis and irreversible adhered to DNA isolated, often reducing its quality and inhibiting PCR amplification. Fig. 1. Agarose gel Electrophoregram of DNA isolated from alcohol fixed fresh leaves of five species of Euphorbiaceae. (lane 1: Ricinus communis, lane 2: Excoecaria robusta, lane 3: Hevea brasiliensis, lane 4: Jatropha multifida, lane 5: Jatropha curcas). The reason for this is that due to the cell death by drying in an electric oven, the dry leaves contain high levels of polysaccharides and polyphenolic compounds that are difficult to separate from DNA (Jobes et al. 1995, Ostrowska et al. 1998), but they are easily identified, because they make the DNA pellet sticky and gelatinous (polysaccharides) or often import a brown colour (polyphenols). In case of grinding the leaves in liquid nitrogen, the protocol described here yielded high molecular weight DNA which ranged from 233 to 296 µg per gram fresh weight with A260/A280 absorbance ratio between 1.80 and 2.00. The highest yield of genomic DNA (336 µg) was recorded in the alcohol fixed fresh leaves of J. multifida which were comparable to those of genomic DNA isolated from liquid nitrogen ground leaves. Thus, the results obtained in the alcohol fixed and liquid nitrogen ground fresh leaves indicated not much difference in terms of quality and quantity of genomic DNA. Fixing the leaves in alcohol not only deactivates the enzymes, but also makes it more amenable to grind in the CTAB buffer. The alcohol fixed fresh leaves appear to be excellent for isolation of genomic DNA when compared to that of liquid nitrogen ground leaves.
Load more

Recommended publications
  • DECOMPOSITION of the RUBBER TREE Hevea Brasiliensis LITTER at TWO DEPTHS
    RESEARCH DECOMPOSITION OF THE RUBBER TREE Hevea brasiliensis LITTER AT TWO DEPTHS Thiago Claudino Gréggio1 , Luiz Carlos Assis1, and Ely Nahas1* A B S T R A C T INTRODUCTION The decomposition of soil litter contributes to Maintenance of a forest ecosystem depends on the soil maintaining agricultural sustainability, since the physical-chemical properties and its interaction with nutrients released by microbial activity are the biotic communities that act, on different temporal determinants of the net productivity of the and spatial scales, in cycling of organic material (OM), agroecosystem. The decomposition of rubber tree consequently providing the nutrients necessary for this (Hevea brasiliensis [Willd. ex A. Juss.] Müll. Arg.) system (Beare et al., 1995). The greater source of leaves located on the surface and buried in at 10 cm residues comes from the OM decomposition of leaf depth in Forest and Savannah (Cerradão) soils litter that is accumulated on the surface of the soil, (Oxisols) was studied, with emphasis on the and the dead roots of the plants (Chadwick et al., 1998; production of CO2 and the monthly variation of the Fioretto et al., 2001; Santa Regina and Tarazona, remaining amounts of litter mass, soluble substances, 2001). cellulose and lignin. To evaluate CO2 production, H. brasiliensis leaves were incubated for 30 days in soils Among the decomposing agents, bacteria and fungus from the 0-2 cm and 10-12 cm layers. CO2 production have a preponderant role due to their greater biomass increased in the 0-2 cm layer in comparison to the 10- and respiratory metabolism (Torres et al., 2005).
    [Show full text]
  • Fecal Metagenomics for the Simultaneous Assessment of Diet
    Srivathsan et al. Frontiers in Zoology (2016) 13:17 DOI 10.1186/s12983-016-0150-4 RESEARCH Open Access Fecal metagenomics for the simultaneous assessment of diet, parasites, and population genetics of an understudied primate Amrita Srivathsan1,2,3*, Andie Ang4, Alfried P. Vogler2,3 and Rudolf Meier1,5 Abstract Background: Rapid habitat loss and degradation are responsible for population decline in a growing number of species. Understanding the natural history of these species is important for designing conservation strategies, such as habitat enhancements or ex-situ conservation. The acquisition of observational data may be difficult for rare and declining species, but metagenomics and metabarcoding can provide novel kinds of information. Here we use these methods for analysing fecal samples from an endangered population of a colobine primate, the banded leaf monkey (Presbytis femoralis). Results: We conducted metagenomics via shotgun sequencing on six fecal samples obtained from a remnant population of P. femoralis in a species-rich rainforest patch in Singapore. Shotgun sequencing and identification against a plant barcode reference database reveals a broad dietary profile consisting of at least 53 plant species from 33 families. The diet includes exotic plant species and is broadly consistent with > 2 years of observational data. Metagenomics identified 15 of the 24 plant genera for which there is observational data, but also revealed at least 36 additional species. DNA traces for the diet species were recovered and identifiable in the feces despite long digestion times and a large number of potential food plants within the rainforest habitat (>700 species). We also demonstrate that metagenomics provides greater taxonomic resolution of food plant species by utilizing multiple genetic markers as compared to single-marker metabarcoding.
    [Show full text]
  • Evaluating the Development and Potential Ecological Impact of Genetically Engineered Taraxacum Kok-Saghyz
    Evaluating the Development and Potential Ecological Impact of Genetically Engineered Taraxacum kok-saghyz DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Brian J. Iaffaldano Graduate Program in Horticulture and Crop Science The Ohio State University 2016 Dissertation Committee: Professor Katrina Cornish, Advisor Professor John Cardina Professor David Francis Professor Allison Snow Copyrighted by Brian J. Iaffaldano 2016 Abstract Natural rubber is a biopolymer with irreplaceable properties, necessary in tires, medical devices and many other applications. Nearly all natural rubber production is dependent on a single species, Hevea brasiliensis. Hevea has several disadvantages, including a long life cycle, epidemic diseases, and rising production costs which have led to interest in developing new sources of rubber with similar quality to Hevea. One species that meets this criterion is Taraxacum kok-saghyz (TK), a widely adapted species of dandelion that can produce substantial amounts of rubber in its roots in an annual growing period. Shortcomings of TK include an inability to compete with many weeds, resulting in poor establishment and yields. In addition, there is variability in the amount of rubber produced, plant vigor, and seed establishment. In order to address these shortcomings, genetic engineering or breeding may be used to introduce herbicide resistance and allocate more resources to rubber production. We have demonstrated stable transformation in Taraxacum species using Agrobacterium rhizogenes to introduce genes of interest as well has hairy root phenotypes. Inoculated roots were subjected to selection by kanamycin and glufosinate and allowed to regenerate into plantlets without any hormonal treatments or additional manipulations.
    [Show full text]
  • El Cultivo Del Hule En México
    Libros Técnicos: Serie Forestal Programa Forestal Colegio de Postgraduados EL CULTIVO DEL HULE EN MÉXICO Gustavo E. Rojo Martínez Rosa Martínez Ruiz Jesús Jasso Mata M. en C. José Concepción Castro Robles Rector Lic. Ismael Gámez Robles Secretario General Lic. Marco Antonio Flores Flores Coordinador General Educativo Lic. Carlos Ernesto Villa Panquián Coordinador General Administrativo Dr. Ernesto Guerra García Coordinador de Investigación Lic. Juan Antonio Delgado Morales Coordinador Unidad Mochicahui Lic. Rosario Rochín Napus Coordinador Unidad Los Mochis Lic. María de Lourdes Osuna Moreno Abogada General Ma. Lourdes Burgos Zazueta Vinculación y Extensión Universitaria Libros Técnicos: Serie Forestal El cultivo del Hule en México 1ª edición, México, 2011. D.R. © Gustavo E. Rojo Martínez Rosa Martínez Ruiz Jesús Jasso Mata Diseño de portada: Gustavo E. Rojo Martínez. Apoyo: Elvia N. Rodríguez Sauceda. ISBN: 968-899-345-1 Impreso y hecho en México Printed and made in Mexico Publicado por: Universidad Autónoma Indígena de México Benito Juárez # 39, C. P. 81890 Tels. (698) 89 2 00 42 Ext. 120. Mochicahui, El Fuerte, Sinaloa. www.uaim.edu.mx Colegio de Postgraduados. Campus Montecillo Programa de Forestal Km. 36.5 Carr. Fed. México-Texcoco, Montecillo, Edo. de México Tel.: 01 595 95 2 02 00 Ext. 1887. Tel. Directo 58 04 59 88 Ext. 1887 Fax.: 58 04 59 88 Ext. 1850. Este libro no puede ser fotocopiado ni reproducido total o parcialmente por ningún otro medio o método sin la autorización por escrito de los editores. Libros Técnicos: Serie Forestal
    [Show full text]
  • X-Ray Diffraction Patterns of Hevea, Manihot, and Other Rubbers
    U. S. DEPARTMENT OF COMMERCE NATIONAL B UREAU OF STANDARDS RESEARCH PAPER RP1218 Part of Journal of Research of the National Bureau of Standards, Volume 23, July 1939 X.RAY DIFFRACTION PATTERNS OF HEVEA, MANIHOT, AND OTHER RUBBERS By George L. Clark. 1 Siegfried T. Gross.2 and W. Harold Smith ABSTRACT When rubber from Hevea brasiliensis is stretched quickly and exposed to a beam of X-rays, a crystal fiber diffraction pattern is obtained. During previous work, done jointly by the National Bureau of Standards and the University of Illinois on sol and gel fractions of this rubber, no pattern was produced by the stretched sol fraction. With the stretched gel fraction, however, the pattern was sharp and intense. Rubber from Manihot glaziovii also may be separated into sol and gel fractions, and in recent work they, too, have been stretched and examined by X-rays. With the stretched Manihot sol, a few interferences were obtained, but many more resulted with the stretched gel. When crystallized by "freezing" at low t empera­ tures for 24 hours, the interferences from the gel again outnumbered those from the sol. The X-ray measurements of Manihot rubber agree with those of Hevea rubber and indicate that the same structure exists in each. Rubbers obtained from latices of Funtumia elastica, Cryptostegia grandijiora, and Castilla elastica were also examined. Their structures, too, were like that of Hevea rubber, and the similarity confirms earlier observations made when X-ray technique was less highly developed. In crystallized specimens, the crystals melted within the range of temperatures previously observed with Hevea rubber.
    [Show full text]
  • PRELIMINARY STUDY on the DISTRIBUTION and CONSERVATION STATUS of the EAST SUMATRAN BANDED LANGUR Presbytis Femoralis Percura in RIAU PROVINCE, SUMATRA, INDONESIA
    25 Asian Primates Journal 8(1), 2019 PRELIMINARY STUDY ON THE DISTRIBUTION AND CONSERVATION STATUS OF THE EAST SUMATRAN BANDED LANGUR Presbytis femoralis percura IN RIAU PROVINCE, SUMATRA, INDONESIA Rizaldi1, Kurnia Ilham1, Irvan Prasetio1, Zan Hui Lee2, Sabrina Jabbar3, Andie Ang3* 1 Department of Biology, Andalas University, Padang, West Sumatra 25163, Indonesia. E-mail: [email protected], E-mail: [email protected], E-mail: [email protected] 2 Environmental and Geographical Sciences, University of Nottingham Malaysia, Semenyih, Selangor, Malaysia. Email: [email protected] 3 Raffles’ Banded Langur Working Group, Wildlife Reserves Singapore Conservation Fund, Singapore 729826. E-mail: [email protected], E-mail: [email protected] * Corresponding author ABSTRACT The East Sumatran Banded Langur Presbytis femoralis percura is a very little known colobine primate, endemic to Riau Province in Sumatra. Nothing much is known of its population size and distribution, except that it was confined in the area between Rokan and Siak rivers. We carried out an eight-day reconnaissance field trip and determined the presence of P. f. percura in seven locations in Riau Province, which extends south of the Siak River, beyond its previously reported range. We also obtained probably the first publicly available full-frontal coloured photos of the taxon in the wild, and photos of the Riau Pale-thighed Langur P. siamensis cana. Considering that the known populations of P. f. percura are restricted to small and isolated forest remnants, and that the remaining forests are rapidly being converted into oil palm plantations, we propose to change the listing of P.
    [Show full text]
  • BRAZIL's “BATTLE for RUBBER” of WORLD WAR II a Dissertation
    TAPPING THE AMAZON FOR VICTORY: BRAZIL’S “BATTLE FOR RUBBER” OF WORLD WAR II A dissertation Submitted to the Faculty of the Graduate School of Arts and Sciences Of Georgetown University In partial fulfillment of the requirements for the Degree of Doctor of Philosophy In History By Xenia Vunovic Wilkinson, M.A. Washington D.C. December 2, 2009 Copyright 2009 by Xenia Vunovic Wilkinson All Rights Reserved ii TAPPING THE AMAZON FOR VICTORY: BRAZIL’S “BATTLE FOR RUBBER” OF WORLD WAR II Xenia Vunovic Wilkinson Dissertation Adviser: Erick D. Langer, PhD. ABSTRACT Japan’s occupation of Southeast Asia in early 1942 cut off more than 90 percent of the global rubber supply to the World War II Allies. Without an adequate supply of this strategic material to meet military-industrial requirements, it was impossible to win the war. The Roosevelt Administration concluded that the success of the Allied war effort could depend on increasing the productivity of rubber tappers who extracted latex from rubber trees dispersed throughout Amazonian rainforests. In response to Roosevelt’s appeal, Brazil’s President, Getúlio Vargas, organized a “Battle for Rubber” to increase rubber production in the Amazon. The authoritarian Brazilian government recruited around 30,000 “rubber soldiers,” mainly from the arid Northeast, and sent them to work on Amazonian rubber estates. This study explores the dynamics of global, national, and regional actors as they converged and interacted with Amazonian society in the Battle for Rubber. Migrant rubber tappers, Amazonian rubber elites, indigenous groups, North American technical advisers, Brazilian government agencies, and the Roosevelt Administration were linked in a wartime enterprise to increase rubber production.
    [Show full text]
  • The Potential of the South American Leaf Blight As a Biological Agent
    Sustainability 2012, 4, 3151-3157; doi:10.3390/su4113151 OPEN ACCESS sustainability ISSN 2071-1050 www.mdpi.com/journal/sustainability Opinion The Potential of the South American Leaf Blight as a Biological Agent Oghenekome Onokpise * and Clifford Louime Florida A&M University—College of Agriculture and Food Sciences, 204 Perry Paige, Tallahassee, FL 32307, USA; E-Mail: [email protected] * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel.: +1-850-561-2127; Fax: +1-850-561-7094. Received: 17 October 2012; in revised form: 11 November 2012 / Accepted: 13 November 2012 / Published: 15 November 2012 Abstract: When asked by the Department of Homeland Security to create potential terrorism scenarios, even “Out of the Box Thinkers” initially failed to come up with the following scenario. Oil tankers, refineries, nuclear plants, etc., are obvious potential terrorists’ targets, and adequate measures are being taken to protect them. However, what if the target were to be a non-food commodity product, such as natural rubber tree plantations located in places as remote as southeast Asian countries like Thailand or Indonesia? Would it be of concern? At first thought “maybe not”, but think again. What could the release of a deadly microorganism (fungus/virus/bacteria) in a rubber tree plantation in Indonesia, Malaysia or Thailand possibly mean to you or the world economy? Keywords: rubber; Hevea brasiliensis; South American Leaf Blight; national security 1. Introduction Natural Rubber tree (Hevea brasiliensis) is native to the Amazon Rainforest. Initially, the Northeast of Brazil was the only habitat in the world where H.
    [Show full text]
  • Citizen Science Program for Critically Endangered Primates: a Case Study from Singapore
    Primate Conservation 2021 (35) Citizen Science Program for Critically Endangered Primates: A Case Study from Singapore Andie Ang1,2, Sabrina Jabbar1, Vilma D’Rozario2 and Jayasri Lakshminarayanan3 1Raffles’ Banded Langur Working Group, Wildlife Reserves Singapore Conservation Fund, Singapore 2Jane Goodall Institute, Singapore 3National Parks Board, Singapore Abstract: Raffles’ banded langur (Presbytis femoralis) is one of three species of non-human primates in Singapore. With only 67 individuals left, it is listed as locally Critically Endangered. Due to its elusive nature, arboreality, and small population size, public awareness of its presence in Singapore is low, and this hampers conservation efforts. We thus initiated a citizen science project on Raffles’ banded langurs in Singapore. Citizen scientists carried out field observations during weekends (08:00–11:00 and 15:30–18:30, with 96 survey assignments per survey cycle of 24 weeks). Overall 143 people were recruited to take part in the surveys. They completed 631 survey assignments from August 2016 to October 2019 (3.5 years), with an average volunteer retention rate of 38%, i.e., 38% volunteers continued to the next cycle while 62% were new volunteers. A total of 157 sightings of Raffles’ banded langurs were recorded, amounting to a 24.9% encounter rate, i.e., one sighting for every four survey assignments. On average, 65.8% volunteers saw the langurs at least once. Using sighting locations, group demographics, high-resolution photographs from citizen scientists, and data collected by researchers, we confirmed five groups of langurs comprising 34 individuals along the survey route—over half of the langur population in Singapore.
    [Show full text]
  • Breeding for Disease Resistance in Hevea Spp. - Status, Potential Threats, and Possible Strategies
    GENERAL TECHNICAL REPORT PSW-GTR-240 Breeding for Disease Resistance in Hevea spp. - Status, Potential Threats, and Possible Strategies Chaendaekattu Narayanan1 and Kavitha K. Mydin1 Abstract Hevea brasiliensis (Willd. ex A. Juss.) Müll. Arg., a forest tree native to the tropical rain forests of Central and South America, has only been recently domesticated outside its natural range of distribution. Almost all of the commercially cultivated clones of H. brasiliensis represent a very narrow genetic base since they originated through hybridization or selection from a few seedlings of so called Wickham germplasm. Hence, the commercial rubber cultivation, due to their genetic vulnerability, is under a constant threat of attack by native as well as exotic diseases and insects. Climate change, which is clearly felt in the traditional rubber growing regions of India, may possibly alter the host-pathogen interactions leading to epidemics of otherwise minor diseases. Pathogenic fungal diseases including Phytophthora-caused abnormal leaf fall (ALF) and shoot rot, pink disease caused by Corticium salmonicolor, Corynespora-caused leaf disease, and powdery-mildew (Oidium sp.) are challenging diseases posing epidemic threats to rubber cultivation. South American leaf blight (SALB) is a devastating disease caused by Microcyclus ulei (=Dothidella ulei) which has prevented large-scale planting of rubber in Brazil due to epidemic outbreaks. The SALB is a looming threat to other rubber growing areas. Hence, it is essential that a global SALB resistance breeding program be implemented to tackle such future threats of epidemics. Hevea clones clearly exhibit variable levels of susceptibility to pathogenic diseases. Hevea clones have been tested for their capacity to produce phytoalexins; a strong correlation was observed between phytoalexin accumulation and clone resistance.
    [Show full text]
  • Signature Redacted Signature of a Uthor
    Prehistoric Polymer Engineering: A Study of Rubber Technology in the Americas by Michael J. Tarkanian B.S., Materials Science and Engineering Massachusetts Institute of Technology, 2000 Submitted to the Department of Materials Science and Engineering in Partial Fulfillment of the Requirements for the Degree of Master of Science in Materials Science and Engineering at the Massachusetts Institute of Technology September 2003 OF TECHNOLOGY 0 2003 Massachusetts Institute of Technology All rights reserved LIBRARIES Signature redacted Signature of A uthor...............................,.......................................... ........ Michael J. Tarkanian Department of Materials Science and Engineering July 7, 2003 Signature redacted C ertified by .................. ........... .......................................... Heather N. Lechtman Professor of Archaeology and Ancient Technology Thesis Supervisor Signature redacted Certified by................................................... ...................... Christine Ortiz Assistant Professor of Materials Science and Engineering Thesis Supervisor Signature redacted Accepted by................ Harry L. Tuller PCfessor of eramics and Electronic Materials Chair, DMSE Graduate Committee AH.CHIves El Prehistoric Polymer Engineering: A Study of Rubber Technology in the Americas by Michael J. Tarkanian Submitted to the Department of Materials Science and Engineering on August 25, 2003 in Partial Fulfillment of the Requirements for the Degree of Master of Science in Materials Science and Engineering
    [Show full text]
  • Laura K. Marsh Colin A. Chapman Editors Complexity and Resilience
    Developments in Primatology: Progress and Prospects Series Editor: Louise Barrett Laura K. Marsh Colin A. Chapman Editors Primates in Fragments Complexity and Resilience Developments in Primatology: Progress and Prospects Series Editor: Louise Barrett For further volumes: http://www.springer.com/series/5852 Laura K. Marsh • Colin A. Chapman Editors Primates in Fragments Complexity and Resilience Editors Laura K. Marsh Colin A. Chapman Global Conservation Institute Department of Anthropology Santa Fe , NM , USA McGill School of Environment McGill University Montreal , QC , Canada ISBN 978-1-4614-8838-5 ISBN 978-1-4614-8839-2 (eBook) DOI 10.1007/978-1-4614-8839-2 Springer New York Heidelberg Dordrecht London Library of Congress Control Number: 2013945872 © Springer Science+Business Media New York 2013 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifi cally the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfi lms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. Exempted from this legal reservation are brief excerpts in connection with reviews or scholarly analysis or material supplied specifi cally for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. Duplication of this publication or parts thereof is permitted only under the provisions of the Copyright Law of the Publisher’s location, in its current version, and permission for use must always be obtained from Springer.
    [Show full text]